Air slide analyzer system and method

ABSTRACT

Systems and Methods for an air slide analyzer for measuring the elemental content of aerated material traveling by air slide. The air slide analyzer has an analyzer having an entrance opening and an exit opening, and an interior tunnel adapted for aerated material conveyed by an air slide; a radiation detector proximal to the analyzer; a neutron source emitting neutrons into material within the analyzer; and a processor to analyze detected information from the radiation detector, wherein emissions from the material being irradiated with neutrons are detected by the radiation detector and analyzed by the processor to provide elemental information of the material in the analyzer.

1.0 RELATED APPLICATION

This application claims priority to U.S. application Ser. No.14/700,416, filed on Apr. 30, 2015, entitled “Air Slide Analyzer Systemand Method,” which claims priority to U.S. Provisional PatentApplication No. 61/996,152, filed Apr. 30, 2014 titled “Air SlideAnalyzer,” the contents of both are hereby incorporated by reference inits entirety.

FEDERALLY-SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with Government support under grant No. 1152704awarded by the National Science Foundation. The Government has certainrights to this invention.

2.0 FIELD

The present invention generally pertains to systems and methods foranalyzing bulk materials. More particularly, it relates to an in-lineanalyzer for bulk materials with a specially designed air slide.

3.0 BACKGROUND

In manufacturing plants, bulk material is transported using varioustechniques. For instance, the material may be transported used usingfront end loaders, physical labor, conveyors, lifts, bucket elevators orpipes. One transportation approach that is in widespread use is totransport the material on a slightly inclined duct of fluidized air,referred to herein as an air slide.

An air slide is a system that uses the force of gravity to move thematerial. Air slides (also known as aeration conveyors) are used toconvey powders using gravity by passing low-pressure air through aporous membrane media into the bed of the material being handled,resulting in the material becoming fluidized. Material movement isachieved by sloping the air slide to match the fluidized angle of reposeof the material. At the correct slope, fluidized material will “flow”with the consistency of a liquid.

Air slides are typically used to transport material that generally has agranular consistency of flour, or powder. Examples of materials that aretransported by air slide include raw meal and finished cement in cementplant operations. In many industries, it is beneficial to havemeasurements of the physical properties and composition of the materialbeing transported. This information is used in various ways, forinstance in verifying that the material is the correct blend or mixtureof material, that the material has the correct material properties, orin using material properties to optimize the manufacturing process.Different measurements can be taken, including the elemental compositionof the material, the molecular composition of the material, the granularsize of the material, the reflectance of the material, the density ofthe material, and so forth. The exact measurements depend on therequirements for the application.

Various systems in the prior art have been developed to addressquasi-real time assessment of moving material, primarily for non-airslide systems. For example, an in-line analyzer that is in wide spreaduse is a conveyor-belt analyzer using a technology called Prompt GammaNeutron Activation Analysis (PGNAA). PGNAA uses thermal neutrons tomeasure the elemental composition of material on a conveyor belt.However, these systems work on conveyor belts and do not work on airslides. This is because both the low density of the material and the airslide geometrical differences render current technology unfavorable forPGNAA. An approach used on air slides is Near Infra-Red (NIR), but thisis a surface measurement, and this measurement is not accurate becauseof inaccuracies due to changing characteristics of the material andlayering in the material. To date, there is no highly accurate systemfor measuring fluidized material in an air slide.

Therefore, there has been a long-standing need in the industry foraccurate, higher-performing air slide analyzers. Various details of suchanalyzers are elucidated in the following description.

4.0 SUMMARY

The following presents a simplified summary in order to provide a basicunderstanding of some aspects of the claimed subject matter. Thissummary is not an extensive overview, and is not intended to identifykey/critical elements or to delineate the scope of the claimed subjectmatter. Its purpose is to present some concepts in a simplified form asa prelude to the more detailed description that is presented later.

An air slide analyzer for measuring the elemental content of aeratedmaterial traveling by air slide is disclosed. The air slide analyzerincludes an analyzer having an entrance opening, an exit opening, and aninterior tunnel adapted for aerated material conveyed by an air slide.The analyzer also includes an air slide that is adjacent to the tunneland a radiation detector proximal to the analyzer. The analyzer has asource of neutrons, which emits neutrons into material within theanalyzer, and a processor to analyze detected information from theradiation detector, wherein emissions from the material being irradiatedwith neutrons are detected by the radiation detector and analyzed by theprocessor to provide elemental information on the material. The analyzeralso includes a mechanism for increasing a mass per length of materialof the material above a mass level per length flowing in a standard airslide section without an analyzer.

In another aspect of the disclosed embodiments, the air slide analyzerdescribed above is provided, wherein the analysis is at least one ofprompt gamma neutron activation analysis (PGNAA), Thermal NeutronAnalysis (TNA), Pulsed Fast Neutron Analysis (PFNA), Pulsed ThermalNeutron Analysis (PTNA), Pulsed Fast Thermal Neutron Analysis (PFTNA)and Fast Neutron Analysis (FNA). The air slide analyzer may furthercomprise a complimentary measurement system using at least one of Laserinduced breakdown spectroscopy (LIBS), Near infrared imaging (NIR),spectral imaging, X-ray diffraction, X-ray fluorescence, and NuclearMagnetic Resonance, wherein the radiation source is at least one of aradioisotope neutron source and a controllable neutron generator. Theair slide analyzer may further comprise an air slide in the tunnel,wherein a portion of the air slide within the air slide analyzer may becomprised of a material that absorbs fewer neutrons than steel oraluminum. The air slide analyzer may have a mechanism wherein at leastone movable gate is disposed within the air slide, and/or a mixer in thetunnel, the mixer mixing material in the tunnel for homogenization,either before or within in a material accumulation area of the tunnel.The air slide analyzer may further comprise at least one of a heater andcooler to heat or cool the detector or control the detector temperature,and/or an active cooling channel between the air slide and the detector,and/or a neutron moderator to optimize signal from the air slideanalyzer. The air slide analyzer may further comprise at least one of agamma ray absorber and/or a neutron absorber disposed about theanalyzer, to minimize direct and/or indirect background radiation thatwould contribute to an external biological radiation dose emanating fromthe air slide analyzer, and/or shielding located on at least one of afront, side, top, bottom and back area arranged to reduce externalradiation for biological shielding, wherein the analyzer may becomprised of a plurality of substantially uniformly shaped individualshielding pieces, enabling the analyzer to be constructed or dismantledin a piece-wise manner. The analyzer may be constructed to accommodatedifferent shielding requirements or different air slide sizes, and mayfurther comprise an opening within the air slide for physically samplingmaterial directly from the air slide and and/or placing a calibrationstandard in the air slide, wherein the air slide may be comprised ofmultiple sections, and the individual air slide section(s) may bereplaced for maintenance or for calibration purposes by a standardsection(s) of an air slide. Furthermore, the accumulation area of theair slide in the body may be designed with a shape and size thatimproves a signal accuracy of the air slide analyzer. The portion of theair slide may be dimensioned from 6″ wide to 36″ wide, as a non-limitingexample, and the material in the air slide could be at least one of: rawmeal, finished cement, a blend of finished cement and aggregates,ready-mix concrete, fly ash, gypsum, limestone, clinker, off-specclinker, bottom ash, slag, beneficiated fly ash, lime, silica fume,ground granulated blast furnace slag, shale, sand, sandstone, iron more,bauxite, volcanic ore, and ash. The air slide analyzer may furthercomprise silos containing at least one of these materials, wherein theprocessor may send information for adjusting an amount of materialsupplied from the silos based on the at least one molecular andelemental composition of the material in the air slide, and/ormeasurement information from one or more cross belt PGNAA systems,wherein the air slide analyzer may be a part of a processing plant.

Additional aspects, alternatives and variations as would be apparent topersons of skill in the art are also disclosed herein and arespecifically contemplated to be included as part of the invention. Theinvention is set forth only in the claims as allowed by the patentoffice in this or related applications, and the following summarydescriptions of certain examples do not in any way limit, define orotherwise establish the scope of legal protection.

5.0 BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a related art chute analyzer.

FIG. 2A is a perspective view of a related art conveyor belt analyzer.

FIG. 2B is a cross-sectional view of the related art conveyor beltanalyzer of FIG. 2A.

FIG. 3 is a diagram of a related art analyzer where the material flowsthorough the analyzer.

FIG. 4 is a perspective view of a related art air slide.

FIG. 5 is a perspective view of an exemplary embodiment of an air slideanalyzer.

FIG. 6 is a cross-sectional view of one embodiment of an exemplary airslide analyzer.

FIG. 7 is a cross-sectional view of an exemplary air slide.

FIG. 8 is a cross-sectional view of another exemplary air slide.

FIG. 9 is perspective view of a modular embodiment of an exemplary airslide analyzer.

FIG. 10 is a cross-sectional view of an embodiment of an exemplary airslide analyzer with multiple detectors.

FIG. 11 is a cross-sectional view of an embodiment of an exemplary airslide analyzer including the source.

FIG. 12 is a cross-sectional view of an embodiment of an exemplary airslide analyzer configurable for various sizes of air slides.

FIG. 13 is a component illustration of control hardware.

FIG. 14 is a schematic illustration of an exemplary slide analyzer in acement manufacturing environment.

6.0 DETAILED DESCRIPTION

6.1 Introduction

A method of analysis for in-line conveyor belt analyzers that is in wideuse is Prompt Gamma Neutron Activation Analysis (PGNAA). PGNAA usesthermal neutrons to measure the elemental composition of material on aconveyor belt. This technique is especially useful for bulk materialanalysis, as the technique is deeply penetrating and can measure most ifnot all of the material on a conveyor belt. Thus, unlike othertechniques such as X-ray diffraction and X-ray fluorescence, which usesurface measurements, PGNAA analyzers are capable of measuring largequantities and depths of material. Another significant benefit of PGNAAis that the measurement is non-contact and PGNAA equipment has few, ifany, moving parts.

As a result of the capability and benefits of PGNAA, PGNAA equipment isin widespread use throughout the coal, cement and minerals markets. Inthe cement market, PGNAA is typically used for the analysis and blendingof raw materials. The raw material from the cement plant is extractedfrom the quarry, mine, silo, or pile, typically crushed, and thenanalyzed using the PGNAA equipment.

Early PGNAA equipment used a drop chute-type of analyzer as shown in therelated art illustration 100 of FIG. 1, having detector 120 and source140 on opposite sides. An example of this system is described in U.S.Pat. No. 4,582,992, titled “Self-Contained, On-line, Real-Time BulkMaterial Analyzer,” by Atwell et al. These types of analyzers wereuseful, but expensive, and difficult to install at a plant. This problemwas solved with the development of on-line conveyor-belt type PGNAAanalyzers. One related art cross-belt analyzer system 200 is shown inperspective and cross-sectional views in FIGS. 2A and 2B, respectively.The mechanics of such a system are described in U.S. Pat. No. 5,396,071,titled “Modularized Assembly for Bulk Material Analyzer,” by Atwell etal. These cross-belt systems were significantly easier to install andfit very well into the factory operations; however, they required anarrangement of detectors 220A, 220B above the source 240. Since thedevelopment of the first PGNAA on-belt analyzers, the designs haveevolved to improve ease of installation and ease of manufacture. ModernPGNAA devices typically mount to the rails of a conveyor belt orstraddle the rails mounting to pads on both sides. The devices do notrequire cutting the conveyor belt, and can be installed and calibratedin a few days.

Other PGNAA analyzers used for on-line and off line analysis have beendeveloped. For example, the analysis of the material can be done througha pipe 380 with externally arranged source 340 and detector 320, asshown in the related art illustration 300 of FIG. 3 and described inU.S. Pat. No. 7,778,783, titled “Method and Apparatus for Analysis ofElements in Bulk Substance,” by Lingren et al. This patent includes adescription of the common types of PGNAA systems, such as staticanalyzers, slurry analyzers, mechanical sampler analyzers, conveyoranalyzer, and drill tailings analyzers.

PGNAA analyzers in service today often have performance issues. Forexample, in cross-belt PGNAA analyzers, layering of material may occur,which will impact the accuracy of the analysis. Techniques have beendeveloped to compensate for this. For example, U.S. Pat. No. 6,657,189,titled “Maintaining Measurement accuracy in Prompt Gamma NeutronActivation Analyzers with Variable Material Flow Rates or Material BedDepth,” by Atwell et al., developed an error correction technique tocompensate for layering.

Another issue that may arise in PGNAA analysis is due to the varyingmoisture content of materials. Different amounts of moisture in thematerial may change the thermal neutron density as a function of thedepth of the material, and as a result may impact the prompt gamma rayproduction and emitted spectrum as a function of material depth. PGNAAanalyzers often have moisture meters to measure the moisture content,and this information may be used to allow for compensation for varyingdegrees of moisture in a material. However, having to use compensationcorrections typically diminishes the accuracy of PGNAA devices.

Bulk material is transported with various approaches, but a great dealof material is transported through conveyor belts. As a result, the vastmajority of PGNAA analyzers to date are of the belt-conveyor type andprovide an elemental analysis of material on a conveyor belt.

In some instances, ‘additive’ materials may be added to themanufacturing process downstream of the conveyor belt analyzer. Forexample, in cement plants, fly ash, slags, baghouse dust or othermaterials may be added to the manufacturing process after the cross beltanalyzer point of measurement, which will result in greater uncertainlyto the composition of the kiln feed.

In the cement industry and other industries, material is transferred byconveyor belt as rock product and ore from the quarry to the point inthe process where it is milled. To prepare the raw material for use inthe cement kiln, the raw material is milled so that it has a powder-likeconsistency similar to that of flour. To transport this material, bucketelevators and air slides are often used, not a conveyor belt. An airslide uses the combination of air and gravity to transport the material.A related art air slide using air and gravity is shown in FIG. 4. Air isblown in from an air chamber below the bulk material. The air goesthrough a porous membrane fabric, and into the tunnel containing thematerial. The air fluidizes the material. By angling the air-slidedownward a few degrees, the fluidized material travels along the airslide with little friction or compressed energy required. However, theapplication of PGNAA measurement systems to air slide systems has neverbeen done because of the low density of the material, which increasesdifficulty in making accurate and timely measurements.

PGNAA technology, such as that of on-belt analyzers, usually requiresthe exposure of many atoms to do an accurate analysis or significanthydrogen content to enhance the reaction rates in low density materials.On conveyor belt or slurry type analyzers, the material may be mineralore or rock/sand product aggregate with bulk density ranging 1.5-1.7g/cc, crushed coal of density 0.8 to 0.9 g/cc but with hydrogenpercentage 3.5 to 6%, or a mineral-water slurry with density 1.1 to1.35% and hydrogen content of 8-10%. Hydrogen in the sample may moderatethe neutrons' energy down to a level where the atoms in the materialhave a significantly greater probability of absorbing neutrons andtherein producing gamma ray emission.

Assuming the detection system is not limited by signal rate, PGNAAmeasurement precision is primarily a function of the number of neutronsinduced and captured in the material being measured (proportional to thetotal mass of material in the measurement zone and the percent hydrogenin the sample, which increases the material neutron captureprobability), or the product of the combined geometric solid angle ofthe detection apparatus, the intrinsic gamma ray efficiency of thedetectors used, and a function of the energy resolution (spectralclarity or acuteness) of detector and signal processing electronics. Inan air slide, the material is in dry powder form: bulk density may below (0.75 to 0.85 g/cc); moisture and hydrogen may be essentially zero;and the material levels in an air slide are generally only 25-50% of theair slide's volume and the air plenum at the bottom is void of material,which results in significantly fewer atoms available on a per volumebasis for analysis.

These considerations present problems with the accuracy of PGNAAtechniques when applied to air slides. It would be beneficial,therefore, to have a high precision elemental analysis of the materialin the air slide. For example, in cement manufacturing, the analysiswould then include any material, such as fly ash, added to the air slideafter the milling stage. Another location where an air slide analyzerwould be valuable is later in the cement manufacturing process, afterthe clinker is milled to a powder, when additives such as gypsum orlimestone are added. An air slide analyzer would provide valuableprocess feedback to allow the operators to validate and optimize themanufacturing process. Also, since material transported by an air slidehas to be sufficiently dry to properly move in an air slide, an airslide analyzer would in part need to address the issue of varyingmoisture content in the material.

An attempt to address the above concerns can be found in U.S. Pat. No.7,924,414, titled “Non-hazardous Bulk Material Analyzer System,” to M.Mound, which is a method of measuring the composition of the material inan air slide using a light source and a spectrometer. However, the lightsource and spectrometer only enable surface measurements, which fallsfar short of analyzing the full composition of the material. Also,biases in the data can result, as the technique is based on the spectralreflectance of the material, and is not a direct measurement of theelemental composition of the material. Yet another issue is that theremay be lighter and heavier materials in the material mixture, and sosegregation and layering is highly likely, such that a surfacemeasurement will not be representative of the entire material travelingthrough the analyzer.

6.2 Overview

In view of the above, various embodiments described herein present anin-line analyzer that measures the elemental composition of materialtransported in air slides. The mechanical arrangement of analyzercomponents in combination with component additions and modifications tothe air slide before, within, and after the analyzing zone is designedto deliver significantly higher performance than conventional PGNAAanalyzer designs that mount around conveyor belts or slurry tubes. Theconfiguration of the PGNAA system geometry (analyzer complete with amodified air slide) will optimize the resulting signal from the system.By using a new unique system design, it is possible to greatly increasethe sensitivity of the PGNAA device. Accordingly, an accurate, highprecision elemental analysis of the material being transported in an airslide can be achieved such that it can be used for monitoring, processcontrol and other uses.

To measure all of the material in the air slide, the technique calledprompt gamma neutron activation analysis (PGNAA) is used. In thistechnique, neutrons enter the material to be analyzed, and from theneutron interaction with the material, gamma rays are emitted by thematerial. The gamma rays emitted by the material from the neutronstimuli are analyzed to determine the elemental composition of thematerial. The embodiments described herein are not limited to PGNAA, butcan also use fast or thermal neutrons, or a combination of fast andthermal neutrons. Terms commonly used are PGNAA, Thermal NeutronAnalysis (TNA), Pulsed Fast Neutron Analysis (PFNA), Fast NeutronAnalysis (FNA), are well-known to those with expertise in this art. Theapproach can be continuous or be in pulsed operations. The source ofneutrons can come from an isotopic source, or alternatively from aneutron generator, or a combination of both. In various embodiments, thesystem includes the air slide transport mechanism, the neutron source,and the radiation detector. The material enters the air slide analyzer,and neutrons diffuse into the material. When the material captures orinelastically scatters the neutrons, gamma rays are emitted within avery small fraction of a second. The emissions (a spectrum of gammarays) are analyzed to determine the elemental composition.

In various embodiments, the system includes a method of providing morematerial for the analysis, which can improve the accuracy of theanalysis. For example, more material is provided by restricting orconfiguring a restriction zone for the flow of material such that thematerial accumulates inside the analyzing zone. At some pointdownstream, the material may be allowed to return to its normal leveland flow characteristics.

Since aerating a material composed of a blend of different densityparticulates having a different chemistry can result in spatialinhomogeneity within the mix flowing in the air slide, the spatialinhomogeneity can undesirably fluctuate depending on the mass flow rate.And depending upon the arrangement of the exemplary analyzing apparatus(source(s), detector(s)) with respect to the material, the materialinhomogeneity can lead to measurement errors. To alleviate thispotential problem, various embodiments may include the option of addinga means of mixing the material “in” the analyzer or “before” thematerial enters the analyzer. To ensure that the analysis is not biasedby a portion of material of a given chemistry entering the analyzer, andbecause of characteristics such as density or lack of fluidization, thesystem can further include a method of ensuring that the material of anyphysical nature remains fluidized and moves through the analyzer withoutholdup.

Since material inside an air slide may be quite hot, as in raw meal, theexemplary embodiments may incorporate a means of ensuring that thetemperature of the detectors and the system is consistent and will notdamage the system.

Various embodiments can be further designed to optimize the systemmeasurement by using a number of different approaches. For example, thephysical locations of the source, detector, material, and the air slidemechanism may be arranged to provide optimal measurement performancewhile ensuring that the system continues to provide consistent flowcharacteristics. The normal air slide structural elements (ducts orchannels) are typically metallic, typically steel. Strong signalsemanate from most metals, reducing the performance of the analyzer.Therefore, in various embodiments the analyzer air slide apparatus isdesigned and fabricated out of a material that results in bettermeasurement performance in neutron irradiation from the analyzer. Thestructural material may be a material of a unique signature or dopedwith a material(s) to provide a unique gamma ray signature that can bedifferentiated from the signatures of the material being analyzed. Thiscan also be a material that has a low cross section such that it absorbsrelatively few neutrons, for example, carbon, or low cross sectionzirconium, etc.

In other embodiments, the system may be modular, such that it can beeasily adjusted and configured for varying sizes of air slides. Themodular pieces can be large or small. Small modules are designed to beeasily carried by hand, such that the analyzer can be installed inlocations where access using a crane or other lifting mechanism is notpossible, or at least extremely difficult to access.

The air slide is often in a critical location such that a shut-down ofthe air slide can potentially stop the manufacturing process. Thus, itis critical that there is a method of ensuring the system does notrestrict the flow of material during maintenance, blockages, breakdowns,or system calibrations. In various embodiments, the air slide analyzermay include a drop-in replacement air slide section that is designed tobe easily installed in place of the special section that is normallyused inside the analyzer, should any flow problem or other failuredevelop. This provides a method of handling many issues that arise withthe air slide, and allows for maintenance on the air slide, repairs onthe air slide, calibration of the air slide, while ensuring that plantoperations are not adversely impacted. Yet another method is to have adiverting gate that allows the material to flow through the analyzer,and to divert the flow around the analyzer if there are flow issues,maintenance requirements or other situations where it is necessary todivert the flow of material. Another aspect that is important isminimizing radiation from the system. Thus, shielding may be extended tothe front or back of the air slide. This may be attached to theanalyzer, or made separate. The overall objective is to minimize thedose to the surrounding areas.

Calibration of the system is often critical to the system performance.In various embodiments, the system can be calibrated by either fittingthe air slide before or after the analyzer with access ports throughwhich calibration standards can be inserted into the analysis zone, orby doing the calibration off-line by decoupling the special air slidesection spanning the analyzer and moving both the air slide section andthe analyzer up, down or laterally away from the air slide to allowinsertion of the calibration standards through the ends of theanalyzer's air slide section. In some embodiments, the analyzer is notequipped with an air slide itself. The air slide analyzer can beattached to the input or discharge end of the air slide to provide thematerial for analysis. Various embodiments described below include anair slide mechanism, which may ensure that the air flow system hasconsistent flow characteristics.

In some embodiments, the analyzing means utilizes an X-ray source(s)producing a broad spectrum of x-rays that irradiate the material in theair slide, a detector or detector array on the opposite side of thematerial where the signal measured is the X-ray source spectrumattenuated by each of the elements composing the material, and a meansof quantifying the elemental composition of the material by utilizingthe physical property that each element has a unique energy-dependentresponse function to incident gamma rays that depends on the atomdensity thickness (g/cm²) of each element in the material composition onthe air slide.

It is understood that for PGNAA systems, optimal performance is usuallyobtained if there is more material inspected rather than less materialinspected. When the material is in powder form, it can blow off of aconveyor belt. Therefore, a more efficient and effective method ofmoving the material when it is in granular or powder form is to move thematerial by an air slide.

FIG. 4 is an illustration 400 of an air slide. The material (shown asarrows) travels in the material chamber 410 while air is blown from thepressurized air chamber 420 into the material chamber 410. The air fromthe air chamber 420 travels “upward” through a porous membrane 430 andlifts up the material in the material chamber 410 to aerate thematerial. The membrane 430 can be of any material, non-limiting examplesbeing a metal screen, air-porous fabric, etc. In some instances themembrane can be vibrated to assist in the lifting up of the material.The air slide is typically on an angle, and as a result, the materialtravels with the inclination of the material chamber 410.

However, it is understood that the air slide can be horizontal or acombination of angled and horizontal (being sectioned accordingly).Moreover, different portions of the air slide can be at differentinclinations (or non-inclinations) within different portions of theanalyzer. An alternate way of moving the material may also be bypneumatics, where the material is blown through a pipe or tunnel—notwidely used because the inherent efficiency of an air slide requiressignificantly less power to operate. The material may be in a powderform, a granular form, but can be prepared so that it is suitable fortransport in the air slide.

FIG. 5 is a perspective illustration 500 of an exemplary air slideanalyzer embodiment. The air slide 501 travels through the analyzer 550having entrance and exit portals for the air slide 501, and the material(not shown) is analyzed as it travels through the analyzer 550. Thetunnel 502 for the air slide 501 allows the material to pass through theanalyzer 550, and the air in the air chamber 503 keeps the materialfluidized. Note that it is also possible to design the air slideanalyzer without an air chamber 503, where the material slides ortravels through the analyzer 550. If it is desired that “fluid” flow ismaintained during analysis, an air chamber system may provide lessdisruptions to the flow of material than other systems. Of course, otherconfigurations for analysis without the use of an air slide may becontemplated without departing from the spirit and scope of thisdisclosure. Further, while FIG. 5 illustrates an analyzer body about theair slide 501, a configuration can be made where the body is absent,wherein the analyzer 550 is devoid of a solid or body that surrounds theair slide 501.

Since most air slides are made of metal, analyzing the material througha metal air slide can affect the signal from the material in theanalyzer 550. Thus, the tunnel 502 and air chamber 503 can be made of amaterial exhibiting low neutron absorption probability; and with a smallpercentage of dopant element, which can simultaneously provide a uniquesignal for overall calibration. Low neutron absorbing materials includecarbon fiber, and other low cross section materials, such as compositematerials or metals with low neutron cross sections. The tunnel 502, airchamber 503 and surrounding material can be designed to optimize thesignal coming from the material traveling through the air slide 501. Theanalysis can still be done through a steel air slide, but utilizing amore neutron transparent material is understood to minimize the signalalteration or loss from the analyzer 550.

In this illustration 500, a source door 508 is shown on the “right” ofthe analyzer 550 for placement of the neutron source. However, thesource(s) and detector(s) may be positioned around other sides of theair slide 501. It should be appreciated that in some embodiments, thesource may be a radioactive isotope or an accelerator or other on-demandneutron/radiation source.

FIG. 6 is a cross-sectional view 600 of an exemplary air slide analyzer,showing the interior tunnel 602 where the material (not shown) travelsthrough, and buffer regions 603, 605 between the non-analyzer portionsof the air slide 620 and the analyzer 650. All neuron activation systemshave a source of neutrons 606 and one or more detectors 604. While FIG.6 illustrates the shown arrangement of sources/detectors 606, 604, otherarrangements may be utilized. For example, the sources 606 may be placedalong the longitudinal axis of the air slide analyzer 650. The neutronsource 606 can be an isotopic source, or alternatively a neutrongenerator can be used. The detector(s) 604 can be configuredlongitudinally or perpendicular, or as required to optimize the signal.As with other neutron-based systems, the detector(s) 604 can be heatedor cooled.

Alternatively, as the material in the air slide 620 may be hot, thesystem may also provide cooling (not shown) in case of hot material suchas hot meal. This embodiment illustrates the use of top and bottombiological shielding material 607 for radiation safety. The exactmaterial used in the body of the analyzer 650 is also selected takinginto account the temperature of the material in the air slide 620, andthe ambient temperature around the analyzer 650. For example, for rawmeal, the meal can be hot, and thus the detector enclosure may includeboth heating and cooling mechanism(s) for the detectors 604. In acommercial embodiment, a cooling channel 644 can be implemented betweenthe air slide 620 and the detector apparatus 604, cooled by variouspassive or active means, non-limiting examples being vents, forced airor compressed air or jets of compressed air cooling by adiabaticexpansion, and so forth.

The exemplary air slide analyzer illustrates the use of a gate 608.Material in the air slide 620 acts similarly to a liquid (seeking anear-horizon level), and thus the use of a gate 608 allows material toaccumulate inside the analyzer 650. This gate 608 essentially acts as adam, such that the material accumulates behind the dam. Using the gate608 to accumulate material will increase the material in the analyzer650, and can increase the resulting signal of the system. The gate 608can be lowered or raised to adjust the accumulation to ensure that theflow is suitable for plant operations or the analyzer operations. Thegate 608 can be in a section that is separate from the analyzer 650, orit can be incorporated into the analyzer 650. The gate 608 can simply bea piece of metal or suitable material that comes up from the bottom, topor side of the assembly and that inhibits the flow of material. It canalso be stationary such that it does not move, similar to a dam with afixed height. A gate 608 or series of gates 608 could be installeddownstream, or upstream, or both to gradually build up the level in themeasurement.

FIG. 7 is a side view illustration 700 of an exemplary air slide 720,with the “below” air chamber 701 and protruding gate 608. The gate 608acts as a dam, and as a result, the material accumulates to a regiondefined in this illustration as 702. The analysis zone may be centrallylocated within the body of the analyzer so as to allow for biologicalshielding of neutron source radiation on each end. The system may beoptimized to analyze material that accumulates in region 702. In variousembodiments, the gate height can be adjusted up or down, on side to sideto allow for differing volumetric areas or for simply allowing a pre-setvolume to build up or pass. Gate(s) 608 are just one method ofaccumulating material in the analyzer, such as for increasing a mass perlength of material of accumulated material above a mass level per lengthflowing in a standard air slide section without an analyzer. There arenumerous other methods or approaches that can be used to accumulatematerial, non-limiting examples being a trough, pit, sectioned area,narrowed region, etc.

The air slide 720 can be comprised of multiple stages or pieces,allowing an individual or group of pieces to be quickly replaced orexchanged as needed. For example, the gate 608 is shown as being part ofthe rightmost piece, which may be individually replaced, in the eventthe gate section requires maintenance.

In another embodiment, the fluidized density of the material in theanalyzing zone can be optimally maximized by fabricating the air plenumsection with a series of Longitudinal sections, each of which has aseparate air supply with adjustable pressure, so as to achieve theoptimum fluidization for the level or height of material above. Pressurevalves can be controlled by a microcomputer or controller based on alevel sensing or mass flow rate apparatus. In some embodiments, a troughmay be used in or outside the analyzer. A valve (such as a V-Ball) mayalso be used in or after the analyzer to increase the amount of materialin the analyzer. Another approach is to narrow the width of the materialchamber, for example to make it narrower. Yet another approach is torestrict the flow downstream, such that the amount material accumulatesin the analyzer. The main objective is to increase the signal byincreasing the amount of material in the analysis region.

For ease of operation, the porous material of the air slide 720 “inside”the analyzer (where predominantly the gamma ray spectral measurementsignal is generated) can be made of the same material used in the restof the air slide 720 to ensure the flow of material in the analyzer isconsistent with the rest of the air slide 720. In some embodiments, itmay be desirable to use a different material, according to designpreference. It should be appreciated that while an air chamber 701 isshown in this embodiment, it is not necessarily required, as thematerial in the analyzer can slide through or be blown through theanalyzer without an air chamber 701. However, for ease of operation andflow consistency, the embodiments described herein are shown with an airchamber 701. Accordingly, it is understood that alternative designs maybe contemplated absent an air chamber by one of ordinary skill in theart, without departing from the spirit and scope of this disclosure.

The material sent through the air slide may have a consistentcomposition, or it may have a composition that is not uniform, and maycause layering. FIG. 8 is an illustration 800 of an embodiment where adisrupter (or homogenizing means) 801, which can be fabricated frommetal or other resilient material, possibly bent on an angle is placedin the air slide 820 to cause disruptions in the material or air flow,such that the material is agitated before it accumulates in region 702.There are other methods for mixing of material for homogenization. Forexample, additional air may be blown or pulsed into region 702. This canbe from the bottom, or sides, or top. This same effect can be done byusing different porous fabric (possibly having different frictional, orporosity, etc. characteristics) in region 702. Alternately, the systemmay include some mechanism of mixing the material as it accumulates inthe 702 region. This can be accomplished by something as simple as apropeller-type mechanism that can be turned and is located in region 702or adjacent to disrupter 801. Accordingly, alternative methods for“mixing” can be employed by one of ordinary skill in the art and areunderstood to be within the purview of this disclosure.

To ensure that the material does not remain static on the gate 608, thegate may include porous material to allow the material to flow throughthe gate. Alternately, there may be opening or holes in the gate 608 toallow for the material to flow through the gate 608, and not just overthe gate 608. An alternate method of ensuring that the material does notaccumulate and stays in region 702 is to open and shut the gate 608, orto tilt or turn the gate 608 at periodic intervals, to allow thematerial to flow through the system. The gate 608 may be of any desiredshape or geometry. Various means can be designed to ensure that staticmaterial does not remain in the accumulation region 702. Further,various means of raising the material level in the analyzing zone can beunder automated control and may utilize level sensing or mass flowfeedback or the by analyzer itself through quantitative measurement ofthe total mass of the constituents analyzed.

In some embodiments, the air slide 820 can have a channel or passage 835for allowing some material to be directed to a separate analyzing device(not shown) for independent or complementary analysis, for example,elemental or molecular analysis, in order to supplement the neutronanalysis being performed. Or, any other section of the air slide 820that experiences passing material can have the channel or passage 835,for example, the gate 608 or other section may have the channel orpassage 835. Moreover, passage 835 may be used to insert an instrumentsuch as for calibration standards or for direct measurement of thepassing material.

Air slides can be located in locations in a plant that may be difficultto access. Thus, in some instances, it is beneficial if the air slideanalyzer can be assembled in locations where a crane or other liftingmeans is challenging or not feasible. FIG. 9 illustrates an embodiment900 where an analyzer shielding 950 is designed with modular parts. Forexample, a block 901 is built out of material suitable for a PGNAAanalyzer, such as polyethylene filled with shielding material, or otherapplicable material. Of course, other materials may be used, accordingto design preference. The design is modular such that each block 901 canbe easily ported to the analyzer installation site, or alternately theanalyzer shielding 950 can be moved as one unit. The block 901 may beconfigured with mating edges or protrusions to align/mate with adjacentblocks, or be “mated” via an adhesive or other coupling compound. Theblock(s) 901 can be substantially uniform in shape, enabling the airslide analyzer to be constructed or dismantled in a piece-wise manner.Use of modular assemblies that are light enough to be carried by handprovides flexibility in the installation location of the analyzershielding 950.

Where physical space is not limited, the entire analyzer shielding 950may be fabricated in a few large modules, or the small modular parts orlarger modules can be externally assembled into one complete assembly.For example, for fitting over an existing air slide, the modules may beconfigured with individually assembled top, bottom, side sections that“fit” around the air slide to expedite assembly at the plant. Othercombinations of “sizes” or geometries or stacking arrangement areunderstood to be within the purview of those skilled in the art.Therefore, alternative assembly or design methods can be used for themanufacture of an exemplary air slide analyzer. The assembly can alsoinclude additional shielding that is used in the front or back of thesystem that surrounds the air slide or part of the air slide. Thisallows for additional safety shielding for the system. This shieldingcan be attached, or in a separate attachment to the system.

FIG. 10 illustrates a cross-sectional view 1000 of an embodiment of anexemplary air slide analyzer 1050 with air slide tunnel 1007 containingmaterial in the “lower” region 1006 of the tunnel 1007. In thisillustration, nine detectors 1008 are used, shown distributed outsidethe “sides” and “top” of the air slide 1001. The number of detectors1008 used can vary from one to many detectors depending on differentfactors such as the size of the air flow chamber, the amount of materialtraveling through the analyzer 1050, the performance required, and otherfactors. Also, the shape of the air slide analyzer 1050, whileillustrated as rectangular, may be any other desired geometrical shape.The neutron source 1002 is located at the bottom below the air chamber1005 of air slide 1001, shown here with shielding and/or moderatingmaterial 1010. Other locations for the neutron source 1002 can beutilized according to design preference. For example, the neutron source1002 can be located inside the air chamber 1005, or the source 1002 canbe located at the side, and the detectors 1008 moved to differentlocations, on either side of the tunnel 1007, or even beside the neutronsource 1002, separated by an adequate amount of neutron attenuatingmaterials. The neutron source 1002 can be an isotopic source, a neutrongenerator 1022, or some combination involving one or both of these withsome other source, if desired. In an exemplary embodiment, the systemcan have provisions for a neutron generator 1022 and an isotopic source1002 that both can be used at the same time, or either one can be used.

Also, it is envisioned that another detector or sensor 1018 (illustratedas directly above the tunnel 1007) can be used in conjunction with theneutron based analysis, such as a Laser inducted breakdown spectroscopy(LIBS), Near infrared imaging (NIR), Nuclear Magnetic Resonance (NMR),X-ray Fluorescence, or X-ray diffraction. Of course, this other sensor1018 may be located at another location in the analyzer 1050 or airslide 1001 or outside the analyzer, according to design preference.

In an alternate embodiment, the air chamber 1005 can be eliminated for avery short lengthwise span, and the neutron source 1002 (or generator1022) may be located in this area. In another alternate embodiment, theneutron source 1002 (or generator 1022) could be located in the actualtunnel 1007. Yet in another embodiment, the neutron source 1002 (orgenerator 1022) could be located in the material 1006. Yet anotherembodiment can have the neutron source 1002 (or generator 1022) locatedin the top of the tunnel 1007 or above the air slide 1001. In short,many alternative configurations and arrangements are possible.

In various embodiments, the size and shape of the air chamber 1005 canbe designed to optimize the signal from the material shown in region1006 traveling through the analyzer 1050. For example, the width of thetunnel 1007 can be constricted to increase the depth of the material inregion 1006 in its lower region (for example, as in a trapezoid or othernarrowing geometry). Alternatively, the tunnel 1007 (and ensuingmaterial occupying region 1006 in tunnel 1007) can be shaped to allowfor overflow of the material in region 1006 to improve the signal orother aspects that may be desirable. This “shaping” of the tunnel 1007(and lower region 1006) has been based on extensive modeling, with theresulting configuration designed to minimize the distance between thegamma ray emission from the material and the detectors and theirrespective configuration, while ensuring that gamma rays are capturedfrom all regions containing the material. The design also minimizes theneutrons that impact the detector ensuring the best signal from thematerial in the analyzer 1050. Shielding material (not shown) for thedetectors 1008 can be various different materials to shield thedetectors 1008 from neutrons traveling into the detectors 1008, or toshield from lower energy gamma rays, or minimize background gamma rays,direct or indirect that would be otherwise absorbed and counted. Tooptimize the signal, the air chamber 1005 depth or size can be reducedor modified so that the neutron source 1002 is located closer to thematerial 1006. For example, the chamber 1005 can have a width optimizedbetween 6″ to 36″, depending the particulars of the air slide 1001.

FIG. 11 is a cross-sectional view 1100 of an another embodiment using aneutron generator 1101 instead of a radioactive (e.g., californium)source. This can be a pulsed or continuous deuterium-deuteriumgenerator, a Deuterium-Tritium generator, or a Tritium-Tritiumgenerator, and so forth. The geometry and shape of the air slideanalyzer 1150 can be modified to improve the performance of the analyzerdepending on the type of material, the flow of material, the flow rate,the required system performance and other factors impacting the systemperformance, capabilities, and cost. As in FIG. 10, if both a neutrongenerator 1101 and an isotopic source (not shown) are used, then theisotopic source can be located proximate the neutron generator 1101.Thus, the system can either use an isotopic source, a neutron generator1101, or both either separately or at the same time.

FIG. 12 is a cross-sectional view 1200 of an air slide analyzer 1250embodiment using smaller blocks 901 for shielding and construction. Thisdesign can handle different size of air slides. For example, theshielding material shown here at locations 1203, 1204, and 1205 can bemade of polyethylene sheet, and its thickness can be varied to accountfor different air slide sizes. For a much wider air slide, the tunnelsize 1007 (1006/1005) can be increased by using more (or re-arranging)blocks 901 and then filing the spacing the spacing between the blocks901 and the air slide with shielding material (as shown, for example, atlocations 1203, 1204, 1205) and other locations requiring shielding. Theamount of emitted radiation can also be adjusted by varying the numberof blocks 901 used either in the width of the system, the height of thesystem, or both. Alternately additional blocks 901 or shielding materialcan be used in front of or behind the analyzer 1250 to decrease theradiation in front of or behind the system. The shielding can be inblocks or other forms, and can either be attached to the system orseparate. Also, shielding and/or moderating material 1210 can be placedproximal to the neutron source 1002, if so desired. Thisshielding/moderating material 1210 can operate to better “direct” theneutrons to the desired section of the air slide.

The analyzer control box 1201 can house the detector electronics, thepower supply, the analyzer computer and other parts of the system. Inthe simplest embodiments, the electronics and power supplies for thesystem are located in this control box 1201, and the analysis computeris located in a remote location, or alternately located inside thecontrol box 1201. Of course, many other different configurations andgeometries are possible.

FIG. 13 is an illustration 1300 of one possible embodiment for thecontrol box 1201 components. Control box 1201 can contain power 1305 forthe detectors 1008, an analog to digital converter 1310 to capture thedata from the detector 1008, one or more processors 1315 with memory1320 to handle and analyze the data, and to store the data. Theinterface 1325 to the system can be provided on a dedicated computer, oralternatively provided through a web-based interface. Neutron-basedanalyzers have been in existence for over 25 years, and alternativecontrol box 1201 implementation paradigms are within the scope of one ofordinary skill in the art.

FIG. 14 is an illustration 1400 of an exemplary air slide analyzer 1450in a commercial cement industry setting. Multiple different silos 1410,1420 contain material such as clinker, off-spec clinker, gypsum,limestone, lime, marble, granite, shale, sand, sandstone, gravel, millscales, iron ore, bauxite, volcanic ores, bottom ash, beneficiated flyash, slag, and so forth. Of course, depending on the type of “cement”being created, other materials may be contemplated. This material is runthrough a ball mill 1430 and then analyzed by the air slide analyzer1450. The measurement information from the air slide analyzer 1450 isused to dynamically adjust, via feedback controls (not shown), themixture of material that is being blended together. Using this method,it is possible to dynamically adjust the material to have the requiredcomposition that is optimal or very close to optimal for the cementplant operations, and provides very consistent product for theend-customers. There are many other possible locations where anexemplary air slide analyzer 1450 can be used, so any of these locationscan be used for the analysis. The exact location and use may varydepending on plant operations and needs of the site.

Another potential application is the analysis of hot meal afterpre-heating or calcining (conversion of carbonated minerals to mineraloxides), just before the hot meal enters the kiln. This can be used tomonitor, control or adjust the materials added after the milling, suchas fly ash and other materials. The material analysis data the systemprovides can also be utilized in synergy with other analyticalinstrumentation (including PGNAA systems) in the plant, other processcontrol software and systems, to dynamically control the manufacturingprocess. The system can also be used to blend raw mix, as well asadditives that are added before and after the milling process infinished cement production. Yet another potential application is withthe analysis of blending of finished cement with aggregate material atready-mix sites.

While the embodiment of FIG. 14 is in the context of a commercial cementindustry setting, it is expressly understood that the exemplary airslide analyzer in the above figures. may also be utilized in otherindustries that require analysis of aggregated materials. Non-limitingexamples may be the food, chemical, pharmaceutical industries, and soforth.

Furthermore, while repeated references are made to PGNAA as the methodof choice, other applicable methods/systems may be implemented. Forexample, where neutrons enter the material to be analyzed, and gammarays emitted, gamma spectroscopy can be performed on the resultingspectra to extract the measurement information. Therefore, the“analysis” mechanism is not limited to PGNAA, but can include neutronactivation analysis that use fast neutrons, thermal neutrons or alltypes of neutrons, which is often referred to in general as neutronactivation analysis. Thus, the various embodiments described herein canencompass PGNAA, as well as analysis using such industrially usedacronyms such as PFNA, PFTNA, PTNA, and other terms common to thosefamiliar with this technology. Accordingly, in some embodiments multipleanalysis mechanisms can be implemented, a first analyzer in a “forward”part of the air slide and a second (or more) analyzer in the “rear” partof the air slide (perhaps performing a different kind of analysis, suchas analysis for heavy element contaminants). Consequently, variouscombinations of sources, detectors, analysis schemes, etc. can beimplemented, according to design preference.

Yet another implementation is to use another sensor in conjunction withthe neutron based analysis, such as a Laser inducted breakdownspectroscopy (LIBS), Near infrared imaging (NIR), or other techniques,and to use this neutron-based measurement to correct or adjust the othersensor, or alternately use the other sensor to adjust the neutronmeasurements. This can be incorporated inside the analyzer or in two ormore separate units. Additional measurement can also be taken andcombined with the system. For example, samples may be extracted at theweir gate or other location, and molecular analysis can be done. Thus,the system could then provide both elemental and molecular analysis.

It should be understood that various elements/features/components of thedescribed embodiments may be reconfigured, altered, modified, accordingto design preference. For example, the air slide analyzer can be onslight angle, horizontal, or at any angle. The detector can be locatedseparately from the analyzer body, the source can be separate from theanalyzer body, and the shielding can be separate from the analyzer body.If the detector, shielding and neutron source are separate parts, theremay be no clear body to the analyzer. The air slide does not have tohave air from below, but the material may be blown or conveyed throughthe analyzer by other means such as by using a steeply inclined surface.To those skilled in the art, the analyzer shape and size andconfiguration can vary. What is consistent is that the material travelsto or from the analyzer by an air slide, and the material composition ismeasured by the analyzer.

It should be further understood that this and other arrangementsdescribed herein are for purposes of example only. As such, thoseskilled in the art will appreciate that other arrangements and otherelements (e.g. machines, interfaces, functions, orders, and groupings offunctions, etc.) can be used instead, and some elements may be omittedaltogether according to the desired results. Further, many of theelements that are described are functional entities that may beimplemented as discrete or distributed components or in conjunction withother components, in any suitable combination and location. For example,the functional blocks, methods, devices and systems described in thepresent disclosure may be integrated or divided into differentcombinations of systems, devices, and functional blocks, as would beknown to those skilled in the art.

Many modifications and variations can be made without departing from itsscope, as will be apparent to those skilled in the art. Functionallyequivalent methods and apparatuses within the scope of the disclosure,in addition to those enumerated herein, will be apparent to thoseskilled in the art from the foregoing descriptions. It is to beunderstood that this disclosure is not limited to particular methods,implementations, and realizations, which can, of course, vary. It isalso to be understood that the terminology used herein is for thepurpose of describing particular embodiments only, and is not intendedto be limiting. The various aspects and embodiments disclosed herein arefor purposes of illustration and are not intended to be limiting, withthe true scope being indicated by the following claims.

The invention claimed is:
 1. An air slide analyzer for measuring theelemental content of aerated material traveling by air slide, the airslide analyzer comprising: an analyzer having an entrance opening and anexit opening, and an interior tunnel adapted for aerated materialconveyed by an air slide; an air slide adjacent to the tunnel; aradiation detector proximal to the analyzer; a source of neutronsemitting neutrons into material within the analyzer; a processor toanalyze detected information from the radiation detector, whereinemissions from the material being irradiated with neutrons are detectedby the radiation detector and analyzed by the processor to provideelemental information of the material in the analyzer; and a mechanismfor increasing a mass per length of material of the material above amass level per length flowing in a standard air slide section without ananalyzer.
 2. The air slide analyzer of claim 1, wherein the analysis isat least one of prompt gamma neutron activation analysis (PGNAA),Thermal Neutron Analysis (TNA), Pulsed Fast Neutron Analysis (PFNA),Pulsed Thermal Neutron Analysis (PTNA), Pulsed Fast Thermal NeutronAnalysis (PFTNA) and Fast Neutron Analysis (FNA).
 3. The air slideanalyzer of claim 1, further comprising a complimentary measurementsystem using at least one of Laser induced breakdown spectroscopy(LIBS), Near infrared imaging (NIR), spectral imaging, X-raydiffraction, X-ray fluorescence, and Nuclear Magnetic Resonance.
 4. Theair slide analyzer of claim 1, wherein the source of neutrons is atleast one of a radioisotope neutron source and a controllable neutrongenerator.
 5. The air slide analyzer of claim 1, wherein a portion ofthe air slide is within the air slide analyzer and the portion iscomprised of a material that absorbs fewer neutrons than steel oraluminum.
 6. The air slide analyzer of claim 1, wherein the mechanism isat least one movable gate disposed within the air slide.
 7. The airslide analyzer of claim 1, further comprising a mixer in the tunnel, themixer mixing material in the tunnel for homogenization, either before orwithin in a material accumulation area of the tunnel.
 8. The air slideanalyzer of claim 1, further comprising at least one of a heater andcooler to heat or cool the detector or control the detector temperature.9. The air slide analyzer of claim 1, further comprising an activecooling channel between the air slide and the detector.
 10. The airslide analyzer of claim 1, further comprising a neutron moderator tooptimize signal from the air slide analyzer.
 11. The air slide analyzerof claim 1, further comprising a least one of gamma ray absorber orneutron absorber disposed about the analyzer, to minimize direct and/orindirect background radiation that would contribute to an externalbiological radiation dose emanating from the air slide analyzer.
 12. Theair slide analyzer of claim 1, further comprising shielding located atleast one of a front, side, top, bottom and back area arranged to reduceexternal radiation for biological shielding.
 13. The air slide analyzerof claim 12, wherein the analyzer is comprised of a plurality ofsubstantially uniformly shaped, individual, shielding pieces, enablingthe analyzer to be constructed or dismantled in a piece-wise manner. 14.The air slide analyzer of claim 1, further comprising an opening withinthe air slide for at least one of physically sampling material directlyfrom the air slide and placing a calibration standard in the air slide.15. The air slide analyzer of claim 1, wherein the air slide iscomprised of multiple sections, wherein the air slide section(s) can bereplaced for maintenance or for calibration by a standard section(s) ofan air slide.
 16. The air slide analyzer of claim 1, wherein theaccumulation area of the air slide in the body is designed with a shapeand size that improves a signal accuracy of the air slide analyzer. 17.The air slide analyzer of claim 1, further comprising material in theair slide, the material being at least one of, raw meal, finishedcement, a blend of finished cement and aggregates, ready-mix concrete,fly ash, gypsum, limestone, clinker, off-spec clinker, bottom ash, slag,beneficiated fly ash, lime, silica fume, ground granulated blast furnaceslag, shale, sand, sandstone, iron more, bauxite, volcanic ore, and ash.18. The air slide analyzer of claim 17, further comprising siloscontaining at least one of the materials.
 19. The air slide analyzer ofclaim 18, wherein the processor sends information for adjusting anamount of material supplied from the silos based on the at least onemolecular and elemental composition of the material in the air slide.20. The air slide analyzer of claim 1, wherein the material measurementis used with measurement information from one or more cross belt promptgamma neutron activation analysis (PGNAA) systems.